Characteristics:

The translucent pale brown or pink body, may reach a length of more than 5 cm. The red pigmented head is characteristic for this species. The oral tentacles are very long, almost half the body length. The rhinophores are lamellated and are white-tipped like the cerata which are loosely organized in clusters. Brownish digestive glands are clearly visible.

Habitat:

Thrives on rocky locations, feeding on hydroids. Can be found on any diveable depth below the tidal zone.

Distribution:

F. bostoniensis may, as the name indicate, be found on both sides of the Atlantic Ocean in addition to western parts of the Mediterranean.